Detection device and detection method
Through the combination of multiple light sources alternate lighting and mobile machines, the problems of high cost and high energy consumption in the existing technology are solved, and efficient and accurate automatic optical detection is achieved.
Patent Information
- Application Number
- CN202410761383.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-29
- Filing Date
- 2024-06-13
- Publication Date
- 2025-07-29
AI Technical Summary
Existing automatic optical detection technology requires high hardware costs and high power consumption when detecting tiny surface undulations or rough surfaces, which is difficult to meet the needs.
Multi-light source lighting is adopted, and light sources of different bands, intensity, and polarization states are used to alternately or simultaneously illuminate the object to be measured, and the reflected light is sensed by mobile machines and sensors to obtain more three-dimensional image data.
It reduces hardware cost and power consumption, while improving the detection accuracy and efficiency, and can more accurately detect defects of the object to be tested.
Smart Images
Figure CN120385672A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a detection device, and particularly to a detection device suitable for Automated Optical Inspection (AOI). Background Art
[0002] Automated Optical Inspection (AOI) uses machine vision to perform inspections on the surfaces of objects, and it has the characteristics of high speed and high precision. However, for some materials with minute surface undulations or relatively high roughness, there are still difficulties in detection and may not necessarily meet the requirements. In the prior art, the Differential Interference Contrast (DIC) technique can be used to highlight the contour contrast of minute surface undulations, or the Dome light can be used to reduce the contrast of rough surfaces to obtain a smooth surface image, and then algorithms are used for identification to determine abnormal defects therein. However, these two detection methods will greatly increase the requirements of AOI for the brightness of the light source, so higher hardware costs are required and larger power losses are caused. In this case, how to provide other effective detection methods is still an urgent problem in this field. Summary of the Invention
[0003] An embodiment of the present disclosure provides a detection device. The detection device includes a first light source, a second light source, a light source controller, and a sensor. The light source controller enables the first light source to irradiate a to-be-detected object in a first time period of a detection stage, and enables the second light source to irradiate the to-be-detected object in a second time period of the detection stage. The sensor continuously senses the reflected light of the to-be-detected object during an exposure period in the detection stage to obtain image data of the to-be-detected object, where the exposure period includes at least part of the first time period and at least part of the second time period.
[0004] Another embodiment of the present disclosure provides a detection method. The detection method includes enabling a first light source to irradiate a to-be-detected object in a first time period, enabling a second light source to irradiate the to-be-detected object in a second time period, and continuously sensing the reflected light of the to-be-detected object during an exposure period to obtain image data of the to-be-detected object. The exposure period includes at least part of the first time period and at least part of the second time period.
[0005] Brief Description of the Drawings
[0006] Figure 1 is a schematic diagram of a detection device according to an embodiment of the present disclosure.
[0007] Figure 2 is a schematic diagram of image data obtained when the to-be-detected object is stationary.
[0008] Figure 3 It is a schematic diagram of image data obtained when the object under test is moving.
[0009] Figure 4 It is Figure 1 an operation timing diagram of the detection device during the detection stage.
[0010] Figure 5 It is Figure 1 a schematic diagram of the moving stage moving the object under test.
[0011] Figure 6 It is a schematic diagram of the detection device according to another embodiment of the present disclosure.
[0012] Figure 7 It is a schematic diagram of the detection device according to another embodiment of the present disclosure.
[0013] Figure 8 It is Figure 7 an operation timing diagram of the detection device during the detection stage.
[0014] Figure 9 It is a schematic diagram of the detection device according to another embodiment of the present disclosure.
[0015] Figure 10 It is a flowchart of the detection method according to an embodiment of the present disclosure.
[0016] Embodiment
[0017] Figure 1 It is a schematic diagram of the detection device 100 according to an embodiment of the present disclosure. The detection device 100 may include a light source 110A, a light source 110B, a light source controller 130, and a sensor 140. In some embodiments, the light source controller 130 may enable the light source 110A and the light source 110B to irradiate the object under test OB1 during the first time period and the second time period in the detection stage, respectively, and the sensor 140 may continuously sense the reflected light of the object under test OB1 during the movement of the object under test OB1 in the detection stage to obtain the image data of the object under test OB1. In some embodiments, the light sources 110A and 110B may be used to provide light of different wavelengths, different intensities, and / or different polarization states. In this case, the object under test OB1 will receive different light source illuminations at different time periods and present different characteristics, and the sensor 140 may continuously sense the images of different characteristic points, thereby increasing the content of the image data of the object under test OB1 and facilitating the defect detection of the object under test OB1. In addition, in the present embodiment, the light sources 110A and 110B may both be bright field light sources. However, the present disclosure is not limited thereto. In some other embodiments, the light sources 110A and 110B may be bright field light sources, dark field light sources, and / or backlight light sources, respectively.
[0018] In addition, in some embodiments, the detection device 100 may further include a moving stage 120. The moving stage can carry the object under test OB1 and move the object under test OB1 during the detection phase. Since the sensor 140 can sense the reflected light of different feature points during the movement of the object under test OB1, more three-dimensional image data formed by superimposing different feature points can be obtained, which is conducive to defect detection of the object under test OB1. In some embodiments, the detection device 100 may further include an image processor 150, and the image processor 150 can perform defect detection on the object under test OB1 based on the image data obtained by the sensor 140.
[0019] Figure 2 is a schematic diagram of the image data obtained when the object under test OB1 is stationary, and Figure 3 is a schematic diagram of the image data obtained when the object under test OB1 is moving. As can be observed from Figure 2 and Figure 3 , the image data obtained during the movement of the object under test OB1 can more clearly present the surface undulations of the object under test OB1, enabling the image processor 150 to perform more accurate detection.
[0020] Figure 4 is an operation timing diagram of the detection device 100 of the present disclosure during the detection phase. As shown in Figure 4 , during the detection phase, the light source controller 130 can energize the light source 110A to irradiate the object under test OB1 in the first period P1, and energize the light source 110B to irradiate the object under test OB1 in the second period P2. In addition, the sensor 140 can continuously sense the reflected light of the moving object under test OB1 during the exposure period ET1 in the detection phase to obtain the image data of the object under test OB1. In some embodiments, the exposure period ET1 may include the first period P1 and the second period P2, however, the present disclosure is not limited thereto. In some embodiments, the exposure period ET1 may only include a part of the first period P1 and a part of the second period P2.
[0021] In some embodiments, the first light source 110A and the second light source 110B can be used to provide lights of different bands. Since lights of different bands may have different penetration powers and refractive indices for the object under test OB1, irradiating different lights can help increase the chance of detecting defects. For example, the first light source 110A can emit visible light, and the second light source 110B can emit invisible light, such as ultraviolet light or infrared light. In addition, in some embodiments, the first light source 110A and the second light source 110B can also be used to emit lights of different intensities and / or lights of different polarization states. For example, the first light source 110A can emit light with a polarization direction parallel to the incident plane (e.g., P polarization state), and the second light source 11BA can emit light with a polarization direction perpendicular to the incident plane (e.g., S polarization state). Since lights of different polarization states may have different penetration powers and refraction angles for different materials (such as crystal and non-crystalline materials), irradiating lights of different polarization states also has the chance to present different features on the object under test OB1, thereby increasing the chance of detecting defects on the object under test OB1.
[0022] In some embodiments, as Figure 4 shown, the first time period P1 and the second time period P2 can at least partially overlap, so that the lights emitted by the first light source 110A and the second light source 110B can simultaneously irradiate the object under test OB1. In some embodiments, the first time period P1 and the second time period P2 can substantially completely overlap. However, in some other embodiments, the first time period P1 and the second time period P2 can also partially not overlap, so that the sensor 140 can respectively sense the image information when only the first light source 110A irradiates or only the second light source 110B irradiates. In some embodiments, the first time period P1 and the second time period P2 can completely overlap, partially overlap, or completely not overlap.
[0023] Figure 5 FIG. is a schematic diagram of the moving platform 120 of the present disclosure moving the object under test OB1. In some embodiments, the moving platform 120 can include rollers and a track, and the object under test OB1 can be carried on the track. In this case, the moving platform 120 can drive the track by rotating the rollers and move the object under test OB1 located thereon in a straight line. However, the present application does not limit that the moving platform 120 needs to include rollers and a track. In some other embodiments, the moving platform 120 can also include other moving parts to move the object under test OB1.
[0024] In Figure 3In this case, the moving stage 120 can move the object under test OB1 along a straight line L1 in the X direction, for example. When the object under test OB1 moves along the straight line L1 towards the right (e.g., the side with an increasing component on the X-axis), a more obvious light and shadow change will occur at the right boundary of the defect F1 of the object under test OB1, enabling the image processor 150 to detect the right boundary of the defect F1 and thus detect the abnormality. Similarly, when the object under test OB1 moves along the straight line L1 towards the left (e.g., the side with a decreasing component on the X-axis), a more obvious light and shadow change will occur at the left boundary of the defect F1 of the object under test OB1, enabling the image processor 150 to detect the left boundary of the defect F1 and detect the abnormality. In some embodiments, the moving stage 120 can move the object under test OB1 back and forth on the straight line L1. In this way, the left and right boundaries of the defect F1 can be highlighted during the movement, enabling the image processor 150 to more accurately detect the defect F1.
[0025] In addition, in some embodiments, the moving stage 120 can also move the object under test OB1 along a straight line L2 in the Y direction to highlight the upper side (i.e., the side with an increasing component on the Y-axis) and / or the lower side (i.e., the side with an increasing component on the Y-axis) of the defect F1 of the object under test OB1. Alternatively, in some embodiments, the moving stage 120 can also move the object under test OB1 along a straight line L3 between the X direction and the Y direction to highlight the upper right side and / or the lower left side of the defect F1 of the object under test OB1.
[0026] Although in Figure 1 the embodiments, the detection device 100 can use the moving stage 120 to move the object under test OB1 during the exposure period of the sensor 140, the present disclosure is not limited thereto. In some other embodiments, the moving stage 120 can also keep the object under test OB1 stationary during the exposure period. In this case, the moving stage 120 can also be replaced with a stationary stage that only has a carrying function and does not move the object under test.
[0027] In Figure 1 the embodiments, the detection device 100 may further include a lens module 160. The lens module 160 may include at least one lens. The lens module 160 can focus the light to facilitate the sensor 140 to sense the reflected light of the object under test OB1. In some embodiments, if the pixel size of the sensor 140 is A and the magnification of the lens module 160 is B, the pixel resolution C can be expressed as In this case, if the speed at which the moving stage 120 moves the object under test OB1 is V, and the length of the exposure period ET1 of the sensor 140 is T, then in some embodiments, to avoid excessive blurring of the image due to the excessive movement range of the object under test OB1 during the sensing process of the sensor 140, the relationship between V, T, and C can be further defined. For example, in some embodiments, the detection device 100 can be set such that V·T ≤ K·C, where K is a predetermined value, such as but not limited to 2, 3.5, 4, or 5. In this way, it is possible to avoid the object under test OB1 moving too long a distance during the exposure period ET1, resulting in an overly blurred image that is not conducive to detection.
[0028] In addition, in Figure 1 the embodiments, the light sources 110A and 110B can both be, for example, bright-field light sources, but the present disclosure is not limited thereto. Figure 6 FIG. is a schematic diagram of a detection device 200 according to another embodiment of the present disclosure. The detection device 200 has a similar structure to the detection device 100, but the detection device 200 can include a light source 110A and a light source 210B, where the light source 110A can be a bright-field light source and the light source 210B can be a dark-field light source. In some embodiments, the light source controller 230 can control the light sources 110A and 210B according to the Figure 4 control timing shown, for example, the light source controller 230 can enable the light sources 110A and 210B to irradiate the object under test OB1 in the first period P1 and the second period P2 (as shown in Figure 4 ).
[0029] In some embodiments, the detection device 100 or 200 can further include more bright-field light sources, dark-field light sources, and / or backlight light sources. Figure 7 FIG. is a schematic diagram of a detection device 300 according to another embodiment of the present disclosure. The detection device 300 has a similar structure to the detection device 100, but the detection device 300 can further include a light source 310C and a light source 310D, where the light sources 110A and 110B can be bright-field light sources, and the light sources 310C and 310D can be dark-field light sources. In some embodiments, the light sources 110A and 110B can be used to emit light of different wavelengths, different intensities, and / or different polarization states. In addition, the light sources 310C and 310D can emit dark-field light of different wavelengths, different intensities, different polarization states, and / or different angles.
[0030] In some embodiments, during the detection stage, light sources 110A, 110B, 310C, and 310D can irradiate the object under test OB1 simultaneously for some periods, or irradiate the object under test OB1 with different light source combinations at different times according to requirements, so as to increase the probability that the image processor 150 can detect defects. In some embodiments, light sources 110A, 110B, 310C, and 310D can be any combination of bright-field light sources, dark-field light sources, and backlight light sources, and can correspond to different wavelengths, different intensities, different polarization states, and / or different incident angles.
[0031] Figure 8 is the operation timing diagram of the detection device 300 of the present disclosure during the detection stage. As Figure 8 shown, during the detection stage, the light source controller 330 can enable the light source 110A to irradiate the object under test OB1 in the first period P1; enable the light source 110B to irradiate the object under test OB1 in the second period P2; enable the light source 310C to irradiate the object under test OB1 in the third period P3; and enable the light source 310D to irradiate the object under test OB1 in the fourth period P4. In addition, the sensor 140 can continuously sense the reflected light of the object under test OB1 during the exposure period ET1 in the detection stage to obtain the image data of the object under test OB1. In some embodiments, the exposure period ET1 can include the first period P1, the second period P2, the third period P3, and the fourth period P4. In some embodiments, the first period P1, the second period P2, the third period P3, and the fourth period P4 can have partially overlapping or non-overlapping parts. In some embodiments, during the exposure period ET1 of the sensor 140, the moving stage 120 can also move the object under test OB1 so that the sensor 140 can superimpose the images of different feature points to facilitate defect detection.
[0032] Figure 9 is a schematic diagram of a detection device 400 according to another embodiment of the present disclosure. The detection device 400 has a similar structure to the detection device 100. However, the detection device 400 can include light sources 410A and 410B, where both light sources 410A and 410B can be dark-field light sources. In some embodiments, light sources 410A and 410B can emit dark-field light of different wavelengths, different intensities, different polarization states, and / or different angles. In addition, in some embodiments, the light source controller 430 can control the light sources 410A and 410B according to, for example, the control timing Figure 4 shown. For example, the light source controller 430 can enable the light source 410A to irradiate the object under test OB1 in the first period P1; enable the light source 410B to irradiate the object under test OB1 in the second period P2.
[0033] Since the sensor 140 of the detection device 400 can continuously sense the reflected light of the object OB1 during the movement of the object OB1 in the detection stage, it is possible to obtain more three-dimensional image data, which is conducive to defect detection of the object OB1. However, in some embodiments, the moving stage 120 can also keep the object OB1 stationary during the exposure period of the sensor 140. In this case, the sensor 140 can still sense different characteristics of the object OB1 under different light sources, which is conducive to defect detection of the object OB1.
[0034] Figure 10 is a flowchart of a detection method M1 according to an embodiment of the present disclosure. As Figure 10 shown, the detection method M1 may include steps S110 to S150, and the method M1 can be executed by using the detection devices 100, 200, 300 or 400.
[0035] For example, in step S110, the detection device 100 can move the object OB1 by using the moving stage 120. In steps S120 and S130, the light source controller 130 can enable the light sources 110A and 110B to irradiate the object OB1 in the first period P1 and the second period P2 respectively (as Figure 4 shown). In addition, in step S140, the sensor 140 can continuously sense the reflected light of the moving object OB1 during the exposure period ET1 to obtain the image data of the object, and in step S150, the image processor 150 can perform defect detection on the object OB1 according to the image data obtained by the sensor 140.
[0036] Since the sensor 140 can sense the reflected light of different feature points during the movement of the object OB1, more three-dimensional image data formed by superimposing different feature points can be obtained, which is conducive to the image processor 150 to perform defect detection on the object OB1. However, in some other embodiments, according to the requirements of the detection operation, step S110 in the method M1 can also be omitted, that is, the object OB1 is kept substantially stationary during the exposure of the sensor 140.
[0037] In some embodiments, the light sources 110A and 110B can be used to emit light of different wavelengths, different intensities and / or different polarization states. In addition, in some embodiments, the first period P1 and the second period P2 may partially overlap, so that the object OB1 can be irradiated by the light emitted by the two light sources 110A and 110B at the same time. In this way, the sensor 140 can sense more abundant image information at the same time, thereby increasing the chance for the image processor 150 to detect defects.
[0038] In some embodiments, when applying method M1 to detection device 300, method M1 may further include enabling light sources 310C and 310D during corresponding time periods (such as Figure 8 time periods P3 and P4). In some other embodiments, method M1 and detection devices 100, 200, 300, and 400 may also use more light sources to increase the image information that sensor 140 can obtain, thereby improving the accuracy of defect detection.
[0039] In summary, the detection devices and detection methods provided by the embodiments of the present disclosure can use different types of light sources, such as but not limited to bright-field light sources, dark-field light sources, and backlight light sources, and each light source can be used to provide light of different wavelengths, different intensities, different polarization states, and / or different angles. In this way, the user can use a combination of different light sources (or only a single light source) at multiple time periods according to needs, so that the object to be measured can present different characteristics, which is beneficial to detecting the defects of the object to be measured.
[0040] In addition, the detection devices and detection methods provided by the embodiments of the present disclosure can also move the object to be measured and sense the reflected light of the object to be measured during the movement of the object to be measured. Since the sensor can sense the reflected light of different feature points during the movement of the object to be measured, more three-dimensional image data formed by superimposing different feature points can be obtained, which is beneficial to defect detection of the object to be measured.
[0041] Although the present disclosure has described the disclosure and its advantages in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the present disclosure as defined by the appended patent application scope. For example, many of the processes described above can be implemented in different ways and replaced by other processes, or combinations thereof.
[0042] In addition, the scope of the present application is not limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, means, methods, and steps described in the specification. As can be easily understood and applied by those of ordinary skill in the art, processes, machines, manufactures, compositions of matter, means, methods, or steps that currently exist or will be developed in the future and perform substantially the same functions or achieve substantially the same functions also fall within the protection scope of the appended patent application scope.
[0043] Symbol Description
[0044] 100, 200, 300, 400: Detection devices
[0045] 110A, 110B, 210B, 310C, 310D, 410A, 410B: Light sources
[0046] 120: Mobile stage
[0047] 130, 230, 330, 430: Light source controller
[0048] 140: Sensor
[0049] 150: Image processor
[0050] 160: Lens module
[0051] OB1: Object to be measured
[0052] ET1: Exposure period
[0053] P1: First period
[0054] P2: Second period
[0055] P3: Third period
[0056] P4: Fourth period
[0057] L1, L2, L3: Straight line
[0058] F1: Defect
[0059] M1: Method
[0060] S110, S120, S130, S140, S150: Steps
Claims
1. A detection device, characterized in that, Comprising: a first light source; a second light source; a light source controller for enabling the first light source to irradiate a test object during a first time period of a detection stage, and enabling the second light source to irradiate the test object during a second time period of the detection stage; and a sensor continuously sensing the reflected light of the test object during an exposure time period in the detection stage to obtain image data of the test object, wherein the exposure time period includes at least part of the first time period and at least part of the second time period.
2. The detection device according to claim 1, further comprising a moving stage for carrying the test object and moving the test object during the exposure time period of the sensor.
3. The detection device according to claim 2, wherein the moving stage moves the test object along a straight line.
4. The detection device according to claim 1, wherein at least a part of the first time period overlaps with the second time period.
5. The detection device according to claim 1, wherein the light emitted by the first light source during the first time period and the light emitted by the second light source during the second time period correspond to different wavelength bands.
6. The detection device according to claim 1, wherein the intensity of the light emitted by the first light source during the first time period is different from the intensity of the light emitted by the second light source during the second time period.
7. The detection device according to claim 1, wherein the light emitted by the first light source during the first time period and the light emitted by the second light source during the second time period have different polarization states.
8. The detection device according to claim 1, wherein the first light source is a bright field light source, a dark field light source or a backlight light source, and the second light source is a bright field light source, a dark field light source or a backlight light source.
9. The detection device according to claim 1, wherein the first light source and the second light source are bright field light sources, and the detection device further comprises at least one dark field light source, wherein the light source controller is further configured to enable the at least one dark field light source to irradiate the test object during at least a third time period of the detection stage, and the exposure time period of the sensor in the detection stage further includes the at least one third time period.
10. The detection device according to claim 1, wherein the first light source and the second light source are dark field light sources that irradiate the test object at different angles.
11. A detection method, characterized in that, Including in a detection stage: Enabling a first light source to irradiate a test object during a first time period; Enabling a second light source to irradiate the test object during a second time period; and Continuously sensing the reflected light of the test object during an exposure time period to obtain image data of the test object; Wherein the exposure time period includes at least part of the first time period and at least part of the second time period.
12. The method according to claim 11, further comprising moving the test object during the exposure time period.
13. The method according to claim 12, wherein the step of moving the test object during the exposure time period includes moving the test object along a straight line.
14. The method according to claim 11, wherein at least one time period of the first time period overlaps with the second time period.
15. The method according to claim 11, wherein the light emitted by the first light source during the first time period and the light emitted by the second light source during the second time period correspond to different wavelength bands.
16. The method according to claim 11, wherein the light intensity emitted by the first light source during the first period is different from the light intensity emitted by the second light source during the second period.
17. The method according to claim 11, wherein the light emitted by the first light source during the first period and the light emitted by the second light source during the second period have different polarization patterns.
18. The method according to claim 11, wherein the first light source is a bright-field light source, a dark-field light source, or a backlight source, and the second light source is a bright-field light source, a dark-field light source, or a backlight source.
19. The method according to claim 11, wherein both the first light source and the second light source are bright-field light sources, and the method further includes enabling at least one dark-field light source to irradiate the object to be measured during at least a third period of the detection stage, wherein the exposure period further includes the at least one third period.
20. The method according to claim 11, wherein the first light source and the second light source are dark-field light sources that irradiate the object to be measured at different angles.